The increasing cost of building materials and the increasing global populations which lack sufficient housing has created the need for permanent structures built with a minimum of materials. Further, the increasing cost of delivering payloads to orbital and sub-orbital platforms has created the need for ultra-lightweight structures and structural support componens. An approach now common in the design of architectural structures is to create thin shells which are congruent to curved surfaces. Examples include the hyperbolic paraboloid (hy-par), the geodesic dome and other domed structures, the Quonset hut and other cylindrical structures, and conical shaped structures. An approach now common in the design of lightweight support structures, such as in air and space craft, is to create truss frameworks or sandwich structural panels. Examples include the octahedron-tetrahedron (oct-tet) truss and hexagonal or honey-comb sandwich panels. Typical design elements for both minimum-material building structures and lightweight structural panels include the transformation of stress loads into tension and compression forces within the structure, and the distribution of stress loads throughout the structure.
Of particular interest to the present invention are shell structures composed of flat two-dimensional materials which are forced into bending, and thus curved to create a structure of sufficient strength. Such structures correspond to surfaces known as developable surfaces, in that they can be made to easily lie flat. Structures corresponding to developable surfaces include cylindrical and conical structures but not spherical or hyperbolicparaboloid shaped structures.
U.S. Pat. No. 3,990,208 issued Nov. 9, 1976 to Charles E. Henderson discloses a method of forming a single conical structure from a two-dimensional panel structure comprising from one to three contiguous quadrants of a theoretical square configuration. The two-dimensional panel structure is flexed into a downwardly opening conical configuration thus creating a single conical structure.
U.S. Pat. No. 2,767,722 issued Oct. 23, 1956 to Gerald N. Smith discloses a foldable umbrella which is deployed by bending a sheet of inexpensive form-sustaining material cut and scored and folded to form a single cone shaped umbrella-like body structure for use as an emergency umbrella.
U.S. Pat. No. 4,509,302 filed Sept. 27, 1982 by Eugene R. Donatelli discloses a building structure formed of a plurality of stiff triangular panels outwardly bowed to form a single conical structure for use as a solarium.
U.S. Pat. No. 1,175,585 issued Mar. 14, 1916 to George J. Berman discloses an umbrella including an outer sheet comprised of a generally flat material which is bent and thus curved to form a single conical surface.
While useful, the above structures do not lend themselves to buildings that can be extended horizontally in multiple sections to create variably configured architectural environments, nor do they lend themselves to the creation of structural support systems suitable for inclusion in the interior portion of structural panels.